The use of flat ribbon multi-conductor electrical cables in the electronics industry is, of course, widespread. Such cables include a plurality of electrical conductors contained in and electrically isolated from each other by electrical insulation. The insulation may be of various electrically non-conductive materials, usually plastic or plastic-like materials such as polyvinylchloride.
Various techniques have been employed to terminate such flat ribbon cables, for example, by connection of the conductors thereof to respective electrical contacts that may be grouped in a male or female socket-like electrical connector housing to facilitate electrical connection of such conductors to other circuits such as by a mating electrical connector or connection device. One such technique, commonly referred to as an insulation displacement connection (IDC) technique, provides for simultaneous connection of plural contacts to respective conductors of the cable. Typically, IDC ribbon cable connectors include multiple housing parts between which the cable is clamped, and usually before or during clamping the plural contacts of the connector puncture the electrical insulation of the cable to connect with respective conductors. The housing parts are mechanically secured in clamping engagement with the cable, and strain relief is usually provided by the clamping strength and/or by the terminal parts of the contacts pierced through the cable insulation.
Another technique for terminating flat ribbon multi-conductor cables is disclosed in U.S. Pat. No. 4,030,799. This technique provides for direct penetration of electrical contacts through the cable insulation to connect with respective conductors therein followed by molding a body of dielectric material directly about at least part of the contacts and cable to secure the same as an integral structure.
Many if not most flat ribbon cable/connector assemblies are intended to couple with a mating connector or connection device of opposite gender such as pin header for a female cable connector or a socket for a male cable connector. In some instances, it may be desirable to couple cables to a pin field or matrix provided on a circuit board or other substrate. The pin field, for example, may be a grid-like arrangement of pins to which multiple cables are to be coupled by respective cable connectors. It is desirable to have cable connectors that are end-to-end and/or side-to-side stackable to minimize space required for same when connected to a pin field or the like, especially wherein the center-to-center spacing of the pins and of the contacts intended to be connected thereto is uniform throughout the rows and columns of the pin field.
Insert molding is a technique that may be used to make the cable termination assembly disclosed in U.S. Pat. No. 4,030,799. Insert molding usually has special cavity configurations to hold contacts in place as strain relief material is molded about and engagement with part of the contacts and shut off requirements to prevent strain relief molding material from engaging other parts of the contacts.
Overflow molding is a technique in which molding material may be molded about another object without the more severe requirements of insert molding. An example of overflow molding is described below and in the parent patent application in which a strain relief molding material is molded directly to a part of a cable without there being any pre-placed and connected contacts about and to which molding material is to be directly molded. Frequently overflow molding is less exacting, difficult, time consuming and expensive than insert molding.
As is described in further detail below, the present invention provides improvements in electrical connectors, especially of the IDC type, and in overflow molding apparatus and techniques for making such connectors.
The invention will be described below with respect to an electrical cable/connector assembly sometimes referred to as a cable termination assembly. In the art the term cable termination or simply termination often refers to a connector placed on an electrical cable. The term cable termination assembly generally often refers to the combination of such a connector and the cable or at least part of the cable. It will be appreciated that a cable termination may be placed at various locations along the length of an electrical cable, including the ends thereof.